Type I sourdough steamed bread made by retarded sponge-dough method

A retarded sponge-dough method was adopted to make type I sourdough steamed bread (SSB). When matured from 9 to 21 h, sourdoughs attained a properly developed state with desirable acidifying and leavening capacity. Optimal parameters were obtained as follows: sourdough maturing time of 15 h, 40% of sourdough, 72% of flour in sponge dough and retarding time of 24 h. SSB under optimized parameters had large specific volume, fine crumb texture and a high sensory score. Flavor compounds in SSB (a total of 85) were more abundant than that in the control. Many aroma-active esters were identified of which ethyl hexanoate was the most abundant. Anti-staling effects were observed, including a great delay of crumb firmness and starch retrogradation. Retarding up to 24 h of sponge-dough allowed sufficient time for microbial metabolism and endogenous enzyme bioconversion, providing SSB with desirable balanced flavor and aromatic characteristics.